1. Field of the Invention
The present invention relates generally to a power charging apparatus and method in a portable terminal, and in particular, to an apparatus and method for using ambient radio frequency (RF) power to charge a battery.
2. Description of the Related Art
Since the initial debut of the cellular concept at Bell Labs in 1947 and the debut of the first-generation (1G) commercial cellular system in Japan in 1979, mobile communication technology has developed toward portable Internet, digital multimedia broadcasting (DMB), and ubiquitous network service, with the migrations from 1G to second generation (2G) and 2G to third generation (3G). People are under exposure to electronic waves and active studies are being conducted to investigate whether electronic waves are harmful to the human body.
The growth of digital convergence has driven portable terminals to offer a variety of functions, which in turn increase power consumption. Moreover, the development of high-speed multimedia mobile communication service further increases the power consumption of the portable terminals including cellular phones and laptop computers. Accordingly, a low-power integrated circuit (IC) and a large-capacity battery are high priorities in the future developmental phase, and the ultimate goal will be development of a charge-free terminal.
With the aim of active provisioning of high-speed mobile communication service, cell radius has recently been decreased enough to cause the appearance of a nano cell and a pico cell. In addition, the use of many service bands is increasing exposure to electronic waves. In this context, a need exists for techniques of actively utilizing ambient RF or micro-wave power.